With the fast development of a 3rd Generation (3G) digital communication technology and the recombination of telecommunication and mobile operators, the operators more and more focus on the seamless access technology and indoor coverage technology for signals in the construction of networks. Good network coverage, particularly indoor coverage, is the key for the fast development of the mobile communications. Under the background of such requirements, an HNB, as a small and low-power base station, has been highly concerned and favored by operators at home and abroad as well as equipment manufactures. On the one hand, the HNB can fast solve the problem of indoor coverage of signals with lower cost, provide a user with a high-speed data communication service and reduce the load of a macro base station; on the other hand, the HNB realizes the combination of fixation and mobility for the operators so as to realize the development of the mobile communications in a family market.
At present, as dedicated resources of private users, the HNB is mainly deployed and applied in indoor places, such as home, school, company, small-scale group area. It can supplement the coverage of an extensive macro cell and provide a user with a high-speed data, voice and multimedia service in the 3G communication system.
The network framework of the HNB mainly includes an HNB and an HNB gateway. The HNB is connected to a core network through the HNB gateway which is in charge of the safety authentication, registration, maintenance management, configuration, and control of the HNB and the like and realizes the data signaling exchanging between the core network and the HNB.
In the HNB, a pilot signal is used for the phase timing of a mobile terminal, the extraction of coherent carrier, the comparison of signal intensity during transition and handover and the like. The pilot signal is ceaselessly sent during the working period of a base station, and the transmit power of the pilot signal, i.e., the pilot power, is about 12% of the total downlink transmit power of a cell in order to ensure that each mobile terminal in the cell can correctly perform demodulation and communication. The increase of the pilot power can expand a signal coverage area, however, overlarge pilot power can cause pilot pollution, interfere pilot signals of other cells, and reduce the power of a downlink service channel of a base station which the cell belongs to, thereby the services supported is reduced due to such effect.
For example, in the HNB, if a pilot signal is leaked out to a room or an area outside the coverage area of the HNB, it will interfere other mobile terminal users in adjacent areas or passing through the area, thereby causing lots of unnecessary mobility events, such as, measurement, cell reselection, handover, and area location update. These mobility events will increase the load of the core network and cause lots of unnecessary signaling interaction between the HNB and the core network.
There are several methods and strategies for controlling the pilot power in the prior art, such as a pilot power fixing method and a pilot power automatically optimizing method. The disadvantage of the pilot power fixing method f is that it is impossible to modify the pilot power timely according to a practical condition and a fixed pilot power is set only when the HNB is initialized and automatically configured. At present, the pilot power automatically optimizing method mainly includes methods for automatically adjusting the pilot power based on measurement, distance and mobility events, but cannot realize the adjustment of the pilot power according to the service types of the mobile terminal.